Entanglement-based secure quantum cryptography over 1,120 kilometres by Yin, J, Li, Y-H, Liao, S-K, Yang, M, Cao, Y, Zhang, L, Ren, J-G, Cai, W-Q, Liu, W-Y, Li, S-L, Shu, R, Huang, Y-M, Deng, L, Li, L, Zhang, Q, Liu, N-L, Chen, Y-A, Lu, C-Y, Wang, X-B, Xu, F, Wang, X-B, Peng, C-Z, Ekert, AK, Pan, J-W